feat: honour Tap station action in widgets

Small widgetURL and medium list Links route through
StationTapAction via FuelStation.tapDestinationURL: Open map
keeps the Maps URL, More info uses a fuelboard://station
deep link (stationID plus coordinate/name fallback).

Deep link carries fallback coords; ContentView presents the
detail sheet when the station is cached, else the map sheet.
Live Activity detailURL upgraded to the same rich link.

Shared/FuelBoardLiveActivity.swift

@@ -9,7 +9,9 @@
 // in Settings → Live Activity (INDEPENDENT of the Stations-tab selection).
 // Everything dynamic lives in ContentState so updates — including a fuel
 // change — apply to the running activity without needing to restart it.
-// Tapping the activity opens Apple Maps driving directions (maps://).
+// Tapping the activity honours Settings → Tap station: Open map opens Apple
+// Maps driving directions (maps://), More info opens the detail sheet in
+// the app (fuelboard://station).
 
 import ActivityKit
 import Foundation

Shared/FuelPriceWidgetViews.swift

@@ -99,7 +99,7 @@ struct FuelPriceWidgetContent: View {
             }
         }
         .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .leading)
-        .modifier(WidgetURLModifier(url: isWidget ? station.widgetDirectionsURL : nil))
+        .modifier(WidgetURLModifier(url: isWidget ? station.tapDestinationURL : nil))
     }
 
     /// How many station rows each family can fit: medium widgets are short
@@ -129,7 +129,7 @@ struct FuelPriceWidgetContent: View {
             }
             ForEach(entry.stations.prefix(maxRows)) { station in
                 if isWidget {
-                    Link(destination: station.widgetDirectionsURL ?? URL(string: "maps://")!) {
+                    Link(destination: station.tapDestinationURL ?? URL(string: "maps://")!) {
                         row(station, cheapest: cheapest)
                     }
                     .buttonStyle(.plain)

Shared/FuelStore.swift

@@ -271,6 +271,30 @@ struct FuelStation: Identifiable, Codable, Equatable {
         URL(string: "maps://?daddr=\(lat),\(lng)&t=d")
     }
 
+    /// In-app deep link to this station's More info sheet. Carries the
+    /// stationID plus coordinate/name fallback so the app can still show the
+    /// map sheet when the station has left the cache.
+    var detailDeepLinkURL: URL? {
+        var components = URLComponents()
+        components.scheme = "fuelboard"
+        components.host = "station"
+        components.queryItems = [
+            URLQueryItem(name: "stationID", value: id),
+            URLQueryItem(name: "lat", value: String(lat)),
+            URLQueryItem(name: "lng", value: String(lng)),
+            URLQueryItem(name: "name", value: name),
+        ]
+        return components.url
+    }
+
+    /// Widget/Live Activity tap destination honouring Settings → Tap station:
+    /// Open map → Apple Maps directions; More info → in-app detail deep link.
+    var tapDestinationURL: URL? {
+        FuelStore.loadStationTapAction() == .showDetails
+            ? detailDeepLinkURL
+            : widgetDirectionsURL
+    }
+
     /// Name of the bundled brand logo asset, or nil if unknown.
     /// Normalizes messy raw brand strings ("SHELL LEEDS ROAD" → "shell").
     var brandImageName: String? {